using System;

using Org.BouncyCastle.Asn1;
using Org.BouncyCastle.Math;
using Org.BouncyCastle.Utilities;

namespace Org.BouncyCastle.Asn1.Pkcs
{
	public class RC2CbcParameter
		: Asn1Encodable
	{
		internal DerInteger			version;
		internal Asn1OctetString	iv;

		public static RC2CbcParameter GetInstance(
			object obj)
		{
			if (obj is Asn1Sequence)
			{
				return new RC2CbcParameter((Asn1Sequence) obj);
			}

			throw new ArgumentException("Unknown object in factory: " + obj.GetType().FullName, "obj");
		}

		public RC2CbcParameter(
			byte[] iv)
		{
			this.iv = new DerOctetString(iv);
		}

		public RC2CbcParameter(
			int		parameterVersion,
			byte[]	iv)
		{
			this.version = new DerInteger(parameterVersion);
			this.iv = new DerOctetString(iv);
		}

		private RC2CbcParameter(
			Asn1Sequence seq)
		{
			if (seq.Count == 1)
			{
				iv = (Asn1OctetString)seq[0];
			}
			else
			{
				version = (DerInteger)seq[0];
				iv = (Asn1OctetString)seq[1];
			}
		}

		public BigInteger RC2ParameterVersion
		{
			get
			{
				return version == null ? null : version.Value;
			}
		}

		public byte[] GetIV()
		{
			return Arrays.Clone(iv.GetOctets());
		}

		public override Asn1Object ToAsn1Object()
		{
			Asn1EncodableVector v = new Asn1EncodableVector();

			if (version != null)
			{
				v.Add(version);
			}

			v.Add(iv);

			return new DerSequence(v);
		}
	}
}
